Effects of Eu and Ca Co-Substitution for the Improvement of Multiferroic Properties of BiFeO3

2016 ◽  
Vol 697 ◽  
pp. 288-292
Author(s):  
Xin Xu ◽  
Qi Fu Yao ◽  
Sheng Peng ◽  
Long Kai Fang ◽  
Wei Wei Mao ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Spin Structure ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Structure Transition ◽  
X Ray ◽  
Multiferroic Properties ◽  
Co Doped

Pure BiFeO3 (BFO), Ca-doped and Eu/Ca-codoped BFO nanoparticles were prepared by using a sol–gel method. The effects of Eu/Ca-codoped on the structural, magnetic and ferroelectric properties of the samples were studied. The X-ray diffraction (XRD) analysis reveals a structure transition in the codoped samples. Co-doped samples were obtained with the best ferromagnetic properties, with the largest remaining magnetization Mr = 0.20 emμ/g. The structure transition may be the main cause for the origin of improved magnetic properties, which destroys the space modulated spin structure of BFO and releases the locked magnetic. In addition, the doping of Eu into BFO can reduce the leakage current and enhance the ferroelectric properties.

scholarly journals ENHANCED FERROELECTRICITY AND FERROMAGNETISM OF (Y, Ni) CO-DOPED BiFeO3 MATERIALS

2018 ◽  
Vol 56 (1A) ◽  
pp. 219
Author(s):  
Dao Viet Thang
Keyword(s):  
Ferroelectric Properties ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Saturation Polarization ◽  
Perovskite Type ◽  
Co Doped

In this study, multiferroicMultiferroic Bi1-xYxFe0.975Ni0.025O3 (x = 0.00, 0.05, 0.10, and 0.15) called as (Y, Ni)                co-doped BiFeO3 materials were synthesized by a sol-gel method.  and characterized by X-ray diffraction diagrams and(XRD), energy-dispersive X-ray (EDX) and vibrating sample magnetization (VSM) measurements demonstrated. The result showed that Bi1-xYxFe0.975Ni0.025O3all investigated materials waspresent a single phase of the perovskite-type rhombohedral structure. Ferromagnetism and ferroelectricity of the Bi1-xYxFe0.975Ni0.025O3 materials have been investigated. Results showed that the co-doping by (Y, Ni) for (Bi, Fe)  have affected in enhancing by the (Y, Ni) co-doping, as a result the ferroelectric polarization and magnetization of BiFeO3. The magnetic characterization indicated that the ferromagnetic behavior wasthe initial BiFeO3 materialwere enhanced with increasing concentration of Y3+ for (Y, Ni) co-substituted of BiFeO3. Which could beion. It is attributed to the defferentdifference of the magnetic momentmoments of Ni2+ and Fe3+, and+ ions, as well as the Y3+-Fe3+,+ and Y3+-Ni2+ super-exchange interaction. Theinteractions. The characteristics of the investigated materials, such as remanent magnetization (Mr), saturation magnetization (Ms), remanent polarization (2Pr) and saturation polarization (2Ps) continuously increase upon increasing in the range of x from 0.00 to 0.15. When x = 0.15, the values of Mr and Ms are 0.078 and 0.794 emu/g, respectively. The values of 2Pr and 2Ps are 16.58 and 27.99 µC/cm2, respectively. Origin of ferromagnetic and ferroelectric properties of Bi1-xYxFe0.975Ni0.025O3 materials will be discussed in this paper.

Dielectric and Ferroelectric Properties of Modified BiFeO3-PbTiO3 Thin Films Derived from Sol-gel Processing

2003 ◽  
Vol 784 ◽  
Author(s):  
JinRong Cheng ◽  
L. Eric Cross
Keyword(s):  
Thin Films ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Gel Processing ◽  
Room Temperature Dielectric Constant

ABSTRACTIn this paper, thin films of La- modified (Bi,La)FeO3-PbTiO3 (BLF-PT) morphotropic phase boundary (MPB) solid solutions have been prepared by using sol-gel processing. A thin Pb(Zr,Ti)O3 (PZT) template layer was introduced to make BLF-PT thin films adhere tightly to the platinized silicon (Pt/Ti/SiO2/Si) substrate. X-ray diffraction (XRD) analysis revealed that BLF-PT thin films were of the perovskite structure without detectable pyrochlore phase annealing at 650–750°C. The cross sectional and plain view images of or our specimen were observed by using the scan electrical microscope (SEM). The room temperature dielectric constant K and tanδ were of ∼800 and 4% respectively, for BLF-PT thin films using a measurement frequency of 1 kHz. Our preliminary experiments indicated that the sol-gel derived BLF-PT thin films have good insulation resistance and measurable dielectric and ferroelectric responses.

ENHANCED MULTIFERROIC PROPERTIES OF BiFeO3 CERAMICS BY Mo DOPING

2011 ◽  
Vol 25 (18) ◽  
pp. 1521-1528 ◽  
Author(s):  
X. ZHANG ◽  
G. Q. ZHANG ◽  
J. MIAO ◽  
X. G. XU ◽  
Y. JIANG
Keyword(s):  
Electrical Properties ◽  
Electric Field ◽  
Phase Structure ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multiferroic Properties ◽  
Mo Doping ◽  
Polarization Electric Field

We have investigated the magnetic and electrical properties of multiferroic BiFe 1-x Mo x O 3 ceramics ( BFMO , x = 0.0%, 0.2%, 0.5% and 0.8%) prepared by the sol–gel method. The phase structure of BFMO samples were confirmed by X-ray diffraction. It was found that the substitution of Mo is responsible for the increasing of the magnetization in BFMO ceramics. Moreover, both dielectric and polarization-electric field properties suggest that the Mo doping could improve the dielectric and ferroelectric properties in BFMO ceramic.

Structure and Magnetic Properties of (Al, Co) Co-Doped ZnO Thin Films

2012 ◽  
Vol 531-532 ◽  
pp. 299-302
Author(s):  
Ping Cao ◽  
Yue Bai
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Al Doping ◽  
X Ray ◽  
Free Carriers ◽  
Structural And Magnetic Properties ◽  
Co Doped ◽  
Main Factor

In this study, Zn0.99Co0.01Al0.015O thin film has been prepared by sol-gel method. The structural and magnetic properties of the sample were investigated. X-ray diffraction spectroscopy analyses indicate that the Co and Al codoping can not disturb the structure of ZnO. No additional peaks are observed in the Zn0.99Co0.01AlxO and Al3+ and Co2+ substitute for Zn2+ without changing the wurtzite structure. The resistance measurements confirm that Al ions increase the free carriers concentration. Based on the above experiments we think the ferromagnetic behavior of the sample could not originate from Co nanoclusters. The presence of free carriers and localized d spins is a prerequisite for the appearance of ferromagnetism. As the result, the carriers generated by Al doping is considered a main factor to induce the ferromagnetic phenomenon.

scholarly journals Modification in Structural, Morphological, Magnetic and Ferroelectric Properties of Calcium-Doped Bismuth Ferrite Nanoparticles

2020 ◽  
Vol 11 (1) ◽  
pp. 123-131
Author(s):  
Nushrat Naushin ◽  
Sadi Md Shahriar ◽  
Oishy Roy ◽  
Ahmed Sharif
Keyword(s):  
Particle Size ◽  
Hysteresis Loop ◽  
Bismuth Ferrite ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Current Characteristics ◽  
Limiting Value

The structural, morphological, magnetic and ferroelectric properties of calcium (Ca) doped bismuth ferrite (BFO) synthesized using a sol-gel method were studied. X-ray diffraction (XRD) analysis followed by Rietveld refinement revealed the lattice distortion of BFO after doping with 6% and 8% Ca. This also led to the reduction in particle size by creating oxygen vacancies, which was observed from the surface morphology using Field Emission Scanning Electron Microscopy (FESEM). The Magnetic properties exhibited some enhancements in saturation magnetization when the particle size was near a limiting value. The reduction in the coercive magnetic field with the increase in dopant concentration was also evident from the M-H hysteresis loop measured by Vibrating Sample Magnetometer (VSM). The Ferroelectric P-E hysteresis loop exhibited an increased symmetry in the hysteresis loop and increase in the polarization with the increase in %Ca. The 8% Ca doped BFO exhibited an incomplete saturation in the hysteresis loop and was evident to exhibit leakage current characteristics. Journal of Engineering Science 11(1), 2020, 123-131

scholarly journals EFFECT OF CO-DOPED RARE-EARTH AND TRANSITION-METAL IONS ON STRUCTURAL, OPTICAL AND MAGNETIC PROPERTIES OF BiFeO3 MATERIAL

2018 ◽  
Vol 54 (1A) ◽  
pp. 96
Author(s):  
Dao Viet Thang
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Transition Metal Ions ◽  
Scattering Data ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Optical And Magnetic Properties ◽  
Xrd Patterns ◽  
Co Doped

Structural, optical and magnetic properties of polycrystalline BiFeO3 and Bi0.9RE0.1Fe0.95Ni0.05O3 (RE = Sm, Y, Nd) prepared by sol–gel method have been investigated. X-ray diffraction (XRD) patterns reveal that all samples crystalize in rhombohedrally distorted perovskite structure belonging to space group R3c. Analyzed results of both XRD and Raman scattering data show an increase of lattice distortion with co-replacing of rare earths and nickel atoms into Bi and Fe sites respectively. All samples exhibit a weak ferromagnetic behavior at room temperature with enhancement of the magnetization of RE and Ni co-doped samples.

scholarly journals Green synthesis and characterization of hexaferrite strontium-perovskite strontium photocatalyst nanocomposites

2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi
Keyword(s):  
Magnetic Properties ◽  
Green Synthesis ◽  
Sol Gel ◽  
Synthesis Method ◽  
Combustion Method ◽  
Lemon Juice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.

Magnetic Properties of Bulk Zn0.95-XMnXFe0.05O2 Prepared by Sol-Gel Method and Subsequent Hot Pressing

2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Sol Gel ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.

Structural and Optical Properties of Al Co-Doped ZnCoO Thin Film

2014 ◽  
Vol 989-994 ◽  
pp. 656-659
Author(s):  
Ping Cao ◽  
Yue Bai
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Al Doping ◽  
X Ray ◽  
Uv Emission ◽  
Uv Absorption Spectroscopy ◽  
Co Doped

Al co-doped ZnCoO thin film has been prepared by a sol-gel method. The structural and optical properties of the sample were investigated. X-ray diffraction and UV absorption spectroscopy analyses indicate that Al3+ and Co2+ substitute for Zn2+ without changing the wurtzite structure. With the Al doping, the visible emission increased and the UV emission decreased, which is attributed to the increase of O vacancies and Zn interstitials.

scholarly journals Effect of Re and Tm-site on morphology structure and optical band gap of ReTmO3 (Re: La, Ce, Nd, Gd, Dy, Y and Tm: Fe, Cr) prepared by sol-gel method

2018 ◽  
Vol 64 (4) ◽  
pp. 381
Author(s):  
Muhammad Tufiq Jamil ◽  
Javed Ahmad ◽  
Syed Hamad Bukhari ◽  
Murtaza Saleem
Keyword(s):  
Band Gap ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Average Grain Size ◽  
Auto Combustion ◽  
Uv Visible

Rare earth nano sized pollycrystalline orthoferrites and orthocromites ReT mO3 (Re = La, Nd, Gd, Dy, Y and T m = Fe, Cr) have been synthesized by sol-gel auto combustion citrate method. The samples have been characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and UV-visible spectroscopy. The samples are single phase as confirmed by XRD analysis and correspond to the orthorhombic crystal symmetry with space group pbnm. Debye Scherer formula and Williamson Hall analysis have been used to calculate the average grain size which is consistent with that of determined from SEM analysis and varied between 25-75 nm. The elemental compositions of all samples have been checked by EDX analysis. Different crystallographic parameters are calculated with strong structural correlation among Re and Tm sites. The optical energy band gap has been calculated by using Tauc relation estimated to be in the range of 1.77 - 1.87 eV and 2.77 - 3.14 eV, for ReFeO3 and ReCrO3, respectively.

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